Various prior art patents disclose a number of sealing arrangements, some for use on rotating shafts, other in pipe joints, axle seals as on railway journal bearings, between multiple rotating parts, as automotive rear axle seals and others between a shaft and a fixed housing.
Examples of prior sealing arrangements are revealed in the patent art such as Perrow U.S. Pat. No. 2,561,884 which reveals a pipe joint seal and discloses an outer face having one or more annular grooves pressed against a wall to form a seal.
Zavoda U.S. Pat. No. 2,851,315 relates to a seal having an inwardly extending flange acting as an inner sealing flange and an outer sealing flange with a cavity between such flanges. A spring maintains the sealing flanges in operative relation to a metal sleeve and openings through the sleeve serve as drain holes.
Kosatka U.S. Pat. No. 3,022,081 is directed to a self-contained fluid seal for use between relatively rotating machine parts wherein a tube of elastomer has a lead-in ring containing auxiliary sealing lips which abut the inner surface of a radial wall.
Paterson U.S. Pat. No. 3,363,952 discloses a dual lip seal on a rotary shaft and is for use in association with a railway axle journal. The seal includes a fluid sealing inner lip and an outer dust sealing lip.
McEwen U.S. Pat. No. 3,727,923 describes a shaft seal having a sealing annulus and a pair of spaced seal lips adapted to engage the shaft. The second lip is biased into contact with the shaft when the first sealing lip becomes worn, thus affording a second service life for the seal. The inner sealing sleeve is interconnected with an outer sleeve and an annular web.
Fryatt U.S. Pat. No. 4,208,059 discloses a rotary shaft lip seal with two annular sealing lips and a baffle providing a partition across the annular space between the lips. The sealing lips are disposed at an angle to the shaft, which tends to draw any leaked fluid back to the body of fluid being sealed.
These patents fail to show a combination seal arrangement including a multiple lip seal contacting a shaft with a hollow chamber between the lips and a radial face on the seal having a rear surface which includes a plurality of circumferential sealing ribs engaging a gear box.